The invention relates generally to common control over multiple medical pumps and more particularly, to a system and method for controlling multiple pumps to form a pump relay system.
Continuity in administering medical fluids through intravenous (“IV”) infusion is desirable in many situations, such as when certain anesthetic medications are being administered or when short-acting medications are being administered to hemodynamically unstable patients. Uninterrupted administration of medication can be achieved for long periods of time by dispensing medication from large medication containers at very low infusion rates. However, such a method is not possible in cases when a needed medication is supplied only in small containers and in cases when a needed medication has a short contextual half life.
Relay systems comprising multiple medication pumps running sequentially to provide continuous infusion therapy are known in the art. Automated relay systems that automatically begin the operation of a second pump upon ceasing the operation of a first pump without the need for manual initiation of that second pump have provided an advantage to medical personnel. However, maintaining continuity in prior relay systems is difficult when they are transported with patients from one location to another. In situations when a syringe has low friction resistance, an unexpected bolus may be injected to the patient when the syringe pump is momentarily raised above the patient during transport. Also, infusion may undesirably be interrupted when the syringe pump is subsequently lowered to the same level of the patient. Such changes in medication administration can have adverse effects in situations that require the very precise and accurate infusion of medication.
In addition to being sensitive to transportation, prior relay systems require much attention from medical staff to ensure that a changeover from an empty syringe to a filled syringe occurs without introducing an unexpected bolus or an interruption in medication administration. Replacement of an empty syringe with a filled syringe often requires carefully purging air from fluid tubing and other fluid communication channels. Purging and other activities required to ensure a successful changeover often require medical staff members to momentarily focus their attention on medical equipment rather than on the patient. However, patients that need continuous medication administration are often in critical or unstable condition and should be monitored very closely. Thus, it is desirable to reduce and simplify the activities that are required to ensure a successful changeover.
Hence those skilled in the art have recognized a need for a more efficient and automated relay pump system and method for sequentially operating on multiple separate medical fluid containers to achieve substantially continuous flow of fluid through a tube from those containers. Those skilled in the art have also recognized a need for a relay system and method that avoids the creation of a bolus of fluid during the relay operation and which is less sensitive to transportation and is less sensitive to frictional and mechanical variations of syringes. The present invention fulfills these and other needs.